Wind turbine

The invention relates to a wind turbine with a rotor having at least one Rotor blade for converting the flow energy of the wind into mechanical energy energy, with an adjustment for individual adjustment of at least one The rotor blade, with a generator for converting the mechanical energy of the The rotor into electrical energy and with an operative connection between the rotor and the generator for transmitting the mechanical energy of the rotor to the Ge generator.

Such wind turbines are part of the prior art. So z. B. shows the German reference book "Wind Turbines" by Erich Hau, Springer-Verlag, 2nd ed., 1996, pages 52, 175, 222-242, 269, 320 such wind turbines. at These known wind turbines may be established by a Rotorblatteinstell angle control the rotor speed and regulate the power output. Furthermore is known Rotorblatteinstellwinkelregelung protection against overspeed the rotor at high wind speeds or during a power failure, in which the generator torque due to unexpected loss. In both cases it comes to the Wind to protect power installation against destruction by too high rotating rotor.

There are essentially two ways of using the blade adjustment a Re bring duzierung the rotor speed: on the one hand can be the Blatteinstell angle cut in the direction of smaller aerodynamic angle, thereby to reduce power consumption of the rotor. On the other hand, it is possible to the adjustment of Rotorblatteinstellwinkels larger adjustment angles to kri matic aerodynamic angle to Errei called stall condition chen. The latter option has the advantage of adjustment shorter path, but brings with it the disadvantage that the Stall (stable) with high Stresses for the rotor and the entire wind turbine is connected. at However, the setting is common that they only average, the entire wind turbine acting wind speed or a certain consider limiting the rotor speed as a start signal for the blade angle setting.

Both of the aforementioned possibilities of the prior art do not take account, that particularly in a large rotor diameter uneven to Distribution of wind conditions can occur on the rotor surface. This has as in turn different loads on individual blades and asymmetric Loads for the drive train of the wind turbine, ie the hub to drive shaft and the respective bearings. Such different asym metric loads occur not only until a certain rotor number or a certain wind speed, but also constantly find during normal operation of the wind turbine instead. The date of the Prior art blade angle control can therefore not limited to Windge schwindigkeitsschwankungen and related load variations in the rotor area react as in the known systems a unified, synchronous Adjust the rotor blades takes place.

With newer systems (see in particular S. 238 of the above reference book) While on the one hand an individual electrical adjustment of each Ro door leaf been proposed; but also finds this proposal under the Assuming a mean wind speed rather than that of the wind turbine acts. This and the further assumption that the wind velocity with the level increases, a fixed, circumferential cyclic correction of the rotor blade is rear angle proposed to the changing loads on the increase in Windge speed with the height to compensate at least partially. Even with the ser Rotorblatteinstelltechnik it is disadvantageous that the pitch of the rotor blades is fixed and therefore not on local and temporary adjustments to the may wind speed in a portion of the rotor react. Even with the therefore sem proposal takes place at about the rotor face seen in local peaks wind speed asymmetric and thus lebensdauerverkürzende Load instead of the components of the wind turbine.

The object of the invention is therefore to avoid the above problems and to provide a wind turbine available in reducing the burden are the result of local and temporary spikes in Windgeschwindig speed may occur in parts of the rotor surface.

This object is achieved by the fact that at a Windenergiean Location of the type mentioned measuring means are provided, the current that pre-stressing a portion of the wind turbine determine, control means see is the minde a desired position of the instantaneous stress Calculate least one rotor blade and the rotor blade using the Verstellvor direction adjust accordingly and connecting means are provided, the connect adjustment and the measuring means to the control means.

Through the wind power plant according to the invention makes it possible, using the Adjusting device for individual adjustment of at least one rotor blade, the Wind turbine on current, locally only on a part of the wind turbine applied stresses, determined by the measuring means, by means of tax slow tune. Thus, it is advantageously achieved that local peaks in the Load of the rotor blades, the hub, final drive and the bearings used be avoided. This in turn has the result that the lifetime of the wind energy plant set up or will not be shortened unconsciously because asymmetric and the life shortening stresses of parts of Windenergiean position can be largely avoided.

Moreover, it allows the wind turbine according to the invention the momen optimal use tane distribution of wind speeds on the rotor surface and, therefore, contribute to an increased power output of the wind power plant, since all blades always with the desired and thus optimum blade angle be driven and therefore the efficiency of each rotor blade towards the We increases ciency of wind turbines of the prior art.

It is particularly preferred that the position of the rotor blade or the rotor blades adapted continuously to the current demands of the wind turbine becomes. In this way it can be ensured that the wind turbine continuously being driven within the optimal range, while front loading lastungsspitzen, triggered by locally available in the rotor field peaks in the Wind speed, is protected.

In a preferred embodiment of the invention the measurement means determine the Determination of local stress of a rotor blade, a rotor on mince prevailing wind speed. For this purpose, before the measuring means given to a rotor blade mounted on the anemometer. Characterized in that the Ane thermometer is placed directly on the rotor blade, is a very precise control the angular position of the rotor blade in response to an increased or lower Wind speed possible. For the measurement of wind speed directly to the place which is home to an adjustment of the wind turbine, namely directly on to be adjusted rotor blade, is a fast and accurate ANPAS measurement of rotor blade angle position to local changes in Windgeschwindig speed possible.

A further preferred embodiment is characterized in that the measuring means a prevailing in a partial section of the rotor portion mechanical Last determine. In this embodiment, by the direct determination of the in a partial section of the rotor applied mechanical stress to Steuermit stuffs given accurate information, enabling them considering the predetermined geometry, load and / or material data a desired Stel ment can identify at least one adjustable rotor blade.

Particularly advantageous in this embodiment, it is when the measuring means a in the adjustable rotor blade determine prevailing mechanical load. Because by the load is determined directly in the rotor blade, can similarly to the above called direct determination of the wind speed at the rotor blade, a very accurate information about the wind speed profile over the rotor area won who the. With such accurate information, the control means are then able, to control a particularly accurate adjustment of the reaction, so that a front existing peak load are rapidly degraded in a partial section of the rotor can.

Another embodiment of the invention having a rotor hub for receiving the Blades has measurement means that an existing in the rotor hub mechanical Measure cal load. Also in this embodiment can be a quick ANPAS make measurement of the rotor blades to the changed load situation. The same applies to Embodiments with an axle journal for supporting the rotor, in which the Measuring means determine a prevailing in the journal load and at a Wind power plant directly to a drive shaft, the rotor and the generator or via a gear to each other, in which the measuring means in one of the Drive shaft or in the bearings of the drive shaft or the journal Vorherr nant load determine. All of the above embodiments allow ge accurate determination of local load conditions in the rotor area and thus a ge precise control of the adjustment means of the control means. It is be more preferably that the measuring means for measuring the mechanical load Deh exhibit opening strip, at the respective loaded parts of wind energy system are mounted. That is, the stretch marks on the rotor leaf, in the interior of the rotor blade on the rotor hub or within the rotor hub, on the journal or in the interior of the journal, on the drive shaft, or be mounted inside the drive shaft or bearings. In all vorgenann th mounting variants is a simple determination of the existing mechanical rule burden and thus the invention individual adjustment of the rotor leaf possible.

A further preferred embodiment of the invention comprises measuring means, which one prevailing at the to be adjusted rotor blade angle of attack of the Win the identify. It is thus advantageously possible to the wind direction of the at flowing wind relative to determine the to be adjusted rotor blade. with the help this measured value, the control means on a in a portion of the Rotor existing Wind Shift react.

In particular, in conjunction with the above to get the Lastmeßmitteln Control means a very accurate picture of the current wind conditions on the Rotor area: by the load measuring means, the control means can absolutely EXISTING dene load taken into account and by the measuring means for determining the free-stream angle is also able - considering the actual Ro torblattstellung - accurate determination of the size of the angle to be adjusted be made. An accurate adjustment in rapidly changing Windver ratios is thus the combined use of Anströmwinkelmessung and load measurement in the rotor blades ensures advantageous. It is special DERS preferred is the measurement of the angle of attack by the rotor blade brought wind vane made.

A further preferred embodiment of the invention is characterized, that a part of a rotor blade section asynchronously to at least one other adjustable Part of another rotor blade is adjustable. Thus can be reduce, especially for large rotor diameters, the construction cost, by preferably the outer section of the rotor blade, because the power generation of rotor largely focused on the outer wing portion, ver runs adjustable.

In an advantageous embodiment of the invention can be the be a agreed momentary stress desired position of the rotor blades or pretend through related to the control means input means. In this way Example, the wind power plant according to the invention on site after installation to possibly unforeseen wind conditions or after repair be adapted to changing material thicknesses or modified airfoils.

Especially advantageous has proven to be the actual value of the rotor blade angle tap off position of an adjusting gear, which together with a View forms the servomotor adjusting. It is particularly advantageous when the control means the adjustment of the rotor blade substantially simultaneously with the Measurement of values ​​of the stretch marks, the anemometer or the Weather vane according to comparison with the actual value of the adjusting means of the Ver alternate engine make. Such an instantaneous response to Belastungsän changes in the area of ​​the rotor blades is an effective reduction of harmful Loads or weight on one side of the rotor ensures.

An advantageous method for adapting a wind energy plant only in a local section of the wind turbine prevailing instantaneous DEMANDS tions is characterized in that measurement means of the instantaneous load a part of the wind power installation is detected and a control means for instantaneous stress desired position of at least one of the rotor blades is determined, and that according to the rotor blade by means of the adjusting device is adjusted accordingly, the adjustment and the measuring means with the control means are connected by means of connecting means. Because of this simple method can be an effective increase of lifetime and efficiency achieve the wind power plant according to the invention.

Further advantageous embodiments are described in the subclaims.

An embodiment of the invention will be with reference to the accompanying described drawings, in which:

<b>Fig.</b> 1 a partial section through a wind according to the invention power installation is;

<b>Fig.</b> 2 is a front view of a wind energy invention system is; and

<b>Fig.</b> 3 is a block circuit diagram, control of which is adjustable The rotor blade in a preferred embodiment of the He is making.

The <b>Fig.</b> 1 shows a wind turbine <b>1</b> in a partial section. The Wind power installation <b>1</b> rests on a (only partially shown) Tower <b>2</b>, On top En de the tower <b>2</b> a housing <b>4</b> placed on the tower. Below the housin ses <b>4</b> is a tower attached to the maintenance platform <b>6</b>, The housing<b>4</b> has back in its (in the drawing enclosed, illustrated right) part of a (Not shown) and a generator control unit shown in dashed lines <b>8th</b> on. The generator is located behind a bulge <b>10</b> the housing <b>4</b> and is via connecting elements <b>12</b> with his (not shown) rotor on the rotor hub <b>14</b> flanged. The rotor hub<b>14</b> and the (only partially shown) Ro door leaves <b>16</b> together form the rotor <b>18</b>, The rotor<b>18</b> with its rotor hub <b>14</b> via bearings <b>20</b> on a journal <b>22</b> stored. The journal<b>22</b> projects through one in the rotor hub <b>14</b> provided opening <b>24</b> through the rotor hub <b>14</b> down by. The journal<b>22</b> is another tower within the housing <b>4</b> with the tower <b>2</b> connected. From the substantially vertically drawn up tower<b>2</b> extends the journal <b>22</b> relative to the horizontal upwards slightly tilted from. The axis tap <b>22</b> is connected to the (not shown) of the generator stator and protrudes through the rotor of the generator and through the opening <b>24</b> the rotor hub <b>14</b> through and is after its exit from the aperture <b>24</b> on the tower of the <b>2</b> side facing away from the rotor <b>18</b> from one end piece <b>26</b> completed.

In turn perpendicular to the axis of the journal <b>22</b> extend the rotor blades <b>16</b> outward. Here come the blades<b>16</b> through openings <b>28</b> in Vorderge housing <b>30</b> therethrough. The front housing<b>30</b> is movable relative to the fixed with the tower <b>2</b> connected housing <b>4</b> and with the hub <b>14</b> connected.

The rotor blades <b>16</b> are connected via a flange to the rotor hub <b>14</b> swiveling connected around its longitudinal axis. A variable displacement motor<b>34</b> is attached to the flange <b>32</b> mounted and adjusted by means of an adjustment <b>36</b> the rotor blade <b>16</b>, Of the adjusting <b>34</b> and the adjusting mechanism <b>36</b> are electric (in <b>Fig.</b> 3 Darge presented) compounds <b>50</b> or. <b>46</b> with the control device <b>8th</b> connected. The Vorderge housing <b>30</b> encloses the rotor hub <b>14</b> with the bearings <b>20</b>, The flange <b>32</b>, The servomotor <b>34</b> and the adjusting mechanism <b>36</b> weathertight. The Vorderge housing <b>30</b> has a cross-sectionally substantially semi-spherical shape.

On the journal <b>22</b> there are stretch marks <b>38</b>, At the rotor hub<b>14</b> there are stretch marks <b>40</b>, The stretch marks<b>38</b> are an elec tric connection <b>42</b> with the control device <b>8th</b> connected. The stretch marks<b>40</b> are a (in <b>Fig.</b> 3 illustrated) electrical connection <b>48</b> the Steuerge advises <b>8th</b> connected.

The <b>Fig.</b> 2 shows parts of the wind turbine <b>1</b> of the <b>Fig.</b> 1 of the rotor side seen. <b>Fig.</b> 2 shows the tower <b>2</b> with the rotor hub attached to its tip <b>14</b>, From the rotor hub,<b>14</b> go star-shaped three rotor blades <b>16</b> out. The rotor foliage <b>16</b> are on the flange <b>32</b> with the rotor hub <b>14</b> connected. For clarity of illustration, the front housing <b>30</b>, The adjusting motor <b>34</b>, The adjusting mechanism <b>36</b>, The journal <b>22</b>, the opening <b>24</b> and the closure piece <b>26</b> from the <b>Fig.</b> 1 is not shown.

At the rotor blades <b>16</b> are wind vanes <b>44</b> for measuring the angle of incidence of the to the rotor blades <b>16</b> impinging wind mounted. The wind vane<b>44</b> are about (in <b>Fig.</b> 3 illustrated) electrical connection <b>52</b> with the control device <b>8th</b> (<b>Fig.</b> 1) connected.

On the basis of the block diagram of <b>Fig.</b> 3, in the following, the functioning of Wind power installation according to the invention described.

During operation of the wind turbine <b>1</b> rotating the rotor <b>18</b> about the axis the journal <b>22</b>, Here, the rotor blades<b>16</b> a specific, using the control unit <b>8th</b>, The adjusting motor <b>34</b> and the adjusting mechanism <b>36</b> pre passed angular position relative to the plane in which the rotor blades <b>16</b> rotate the Rotor plane. The instantaneous angle α_currently the rotor blades <b>16</b> relative to the Rotor plane is supplied to the control unit <b>8th</b> of the adjusting <b>16</b> as the actual value of the mo instantaneous position of the rotor blade <b>16</b> via an electrical connection <b>46</b> about averages. Simultaneously, the control unit receives<b>8th</b> of the stretch marks <b>38</b>Attached to the journal <b>22</b> are fixed values ​​on the current load on the axle journal <b>22</b> via line <b>42</b> ( "Load signal journal" of <b>Fig.</b> 3). Just if simultaneously with the transmission of the current position angle of the rotor blades <b>16</b> The ECU receives <b>8th</b> of the stretch marks <b>40</b> on the rotor hub via the administration <b>48</b> Measured values ​​of the current load on the rotor hub <b>14</b> ( "Load signal Hub "of <b>Fig.</b> 3). The control unit sets<b>8th</b> by means of stretch marks <b>38</b>. <b>40</b> one-sided loading of the rotor fixed, so are the controller <b>8th</b> Be under account the current position angle α_currently the rotor blades <b>36</b> and the current, from the wind vane <b>44</b> determined angle of attack β a signal α_new via line <b>50</b> to the adjusting <b>34</b> for adjusting the corre relevant rotor blade <b>16</b> α by the difference_new - α_currently,

Characterized that the control unit <b>8th</b> continuously the values ​​of stretch marks <b>38</b> and <b>40</b> receives and quasi instantaneously considering the also constantly via line <b>52</b> to the control unit <b>8th</b> transmitted inflow angle β the Ar beitsbefehl to the adjusting <b>34</b> for setting a new angle of the rotor foliage <b>16</b> publishes, on-line associated with a change in load conditions in Area of ​​the rotor to adapt the position of the rotor blades <b>16</b> instead, thus an online balance unbalanced loads on the rotor <b>18</b>,

As an alternative to the measurement of the instantaneous load on the wind turbine by stretch marks on the rotor hub and axle pin is also a Belastungsmes solution directly on the rotor blades by corresponding stretch marks conceivable.

Finally, it should be noted that the various signals (ie "load signal Hub" <b>40</b>, "Load signal journal" <b>38</b>, "Current angle α_currently" <b>46</b> and "Angle of attack β" <b>53</b>), Which used to determine the ideal blade angle be, either can be used together or alternatively.